Bruce Levet, a barrister with Henry Parkes Chambers, told Lawyers Weekly that he has previously written to the government to alert them to his concerns.

"Put yourself in the shoes of a barrister who might be acting in the first case to come before the Court." He said. "If you have a good case, you might run a defence on the facts, but if you are not able to do that, you would challenge the jurisdiction of the Court to hear the matter.

"I think there would be a very strong chance that such a defence would be successful."

On 24 June, Attorney-General Robert McClelland introduced legislation into Federal Parliament to establish the new Military Court of Australia, which is earmarked to start hearing cases in late 2011.

The new court would replace the defunct Australian Military Court (AMC), which was found to be unconstitutional by the High Court last year.

Levet's comments come in the wake of a decision by Justice Virginia Bell of the High Court yesterday that it would hear a challenge by a former army captain into a decision by the AMC.

Levet is representing Paul Nicholas, a 26 year army veteran, who was sacked after the AMC found him guilty of attempting to pervert the course of justice in a case relating to the alleged improper claiming of $1900 of expenses.

Enacted by the Howard government in October 2007, the AMC made between 130 and 171 decisions before it was declared unconstitutional.

Even though the government passed legislation to ensure penalties handed down by the AMC are imposed, Levet believes that if the High Court rules in favour of Nicholas in this matter, it would throw into doubt the legality of all of the previous decisions of the AMC.

The Commonwealth has until 16 November to file its defence.